This application generally relates to compasses, and more particularly to, fluid or low friction compasses including a magnetized material that is buoyant or nearly buoyant.
A magnet in a compass uses the weak magnetic field of the Earth to align it with the poles of the earth. The torque force to align the magnet with the Earth's magnetic field is very low. As such, friction on the indicating magnet must be kept very low or the magnet will not exert sufficient force to overcome the friction.
Typical compasses include an arrow or solid disk that is suspended or supported on a needle point at the center of gravity. The needle point or suspension provides an ultra-low friction point that corresponds with the axis of torque rotation. When a needle point is used the center of the magnet has to be supported or suspended to work, thereby limiting the geometry of the magnet such that magnets having hollow centers cannot be used.
It would be desirable to provide a simpler more reliable fluid or low friction magnetic compass free from geometric limitations.